This disclosure relates to methods of manufacturing a semiconductor device, and also relates to a method of manufacturing a semiconductor device in which a metal contact is self-aligned when interconnection lines are formed using a double patterning process.
As the degree of integration of semiconductor devices increases, spaces between devices become smaller and an area in which each device is to be formed gradually becomes smaller. Accordingly, sizes of contact areas are reduced and thereby an alignment margin in a photolithography process is reduced. As a result, contact failures may occur. A rapidly reducing design rule limits forming desired patterns using a photolithography process. Thus, in forming an interconnection line and a contact hole, it is beneficial to overcome a limitation of a photolithography process and secure a misalignment margin.
Currently, a contact plug connecting a substrate and/or impurity regions in the substrate is formed before an interconnection line is formed and then an interconnection line is formed to be connected to the contact plug.